Bacillus Calmette-Guérin (BCG)-Cell Wall Skeleton as Immunotherapeutic Option for BCG-Refractory Superficial Bladder Cancer

Although intravesical instillation of Mycobacterium bovis bacillus Calmette-Guérin (BCG) is the most successful cancer immunotherapy for superficial bladder cancer, the serious side effects are frequently arisen by using live mycobacteria. To allow less toxic and more potent immunotherapeutic agents following intravesical BCG treatment for superficial bladder cancer, noninfectious immunotherapeutic drug instead of live BCG would be highly desirable. Recently, immune-enhancing adjuvants are considered an effective vaccine immunotherapy for cancer, providing enhanced antitumor effects and boosted immunity. The BCG-cell wall skeleton (BCG-CWS), the main immune active center of BCG, is a potent candidate as a noninfectious immunotherapeutic drug instead of live BCG against bladder cancer. However, the most limited application for anticancer therapy, it is difficult to formulate a water-soluble BCG-CWS due to the aggregation of BCG-CWS in both aqueous and nonaqueous solvents. To overcome the insolubility and improve the internalization of BCG-CWS into bladder cancer cells, it should be developed the lipid nanoparticulation of BCG-CWS, resulting in improved dispensability, stability, and small size. In addition, powerful technology of delivery systems should be applied to enhance the internalization of BCG-CWS, such as encapsulated into lipid nanoparticles using novel packaging methods. Here, we describe the progress in research on effects of BCG-CWS for cancer immunotherapy, development of lipid-based solvent, and packaging method using nanoparticles with drug delivery system.

Application of Bioprinting to Cancer Research

Three-dimensional (3D) printing is an additive manufacturing process by which precursor materials are deposited layer by layer to form complex 3D geometries from computer-aided designs, and bioprinting offers the ability to create 3D architecture living cells. Bioprinting methods have been developed rapidly pattern living cells, biological macromolecules, and biomaterials, and an advantage of the 3D microenviroment over traditional 2-dimensional cell culture is the ability to obtain more accurate and reliable data from model about tumor formation, progression, and response to anticancer therapies. This review focuses on recent advances in the use of biopriniting technologies for cancer research, bioprinting physiologically relevant testing platforms for anticancer drug development, and computational modeling for improvement bioprinting technique.

The Present and Future of the Cancer Microenvironment Bioprinting

Cancer is the tissue complex consisted with heterogeneous cellular compositions, and microenvironmental cues. During the various stages of cancer initiation, development, and metastasis, cell–cell interactions as well as cell-extracellular matrix play major roles. Conventional cancer models both 2-dimensional and 3-dimensional (3D) present numerous limitations, which restrict their use as biomimetic models for drug screening and fundamental cancer biology studies. Recently, bioprinting biofabrication platform enables the creation of high-resolution 3D structures. Moreover this platform has been extensively used to model multiple organs and diseases, and this versatile technique has further found its creation of accurate models that figure out the complexity of the cancer microenvironment. In this review we will focus on cancer biology and limitations with current cancer models and we discuss vascular structures bioprinting that are critical to the construction of complex 3D cancer organoids. We finally conclude with current literature on bioprinting cancer models and propose future perspectives.

Poloxamer 407 Hydrogels for Intravesical Instillation to Mouse Bladder: Gel-Forming Capacity and Retention Performance

PURPOSE: Poloxamer 407 (P407) thermo-sensitive hydrogel formulations were developed to enhance the retention time in the urinary bladder after intravesical instillation. MATERIALS AND METHODS: P407 hydrogels (P407Gels) containing 0.2 w/w% fluorescein isothiocyanate dextran (FD, MW 4 kDa) as a fluorescent probe were prepared by the cold method with different concentrations of the polymer (20, 25, and 30 w/w%). The gel-forming capacities were characterized in terms of gelation temperature (G-Temp), gelation time (G-Time), and gel duration (G-Dur). Homogenous dispersion of the probe throughout the hydrogel was observed by using fluorescence microscopy. The in vitro bladder simulation model was established to evaluate the retention and drug release properties. P407Gels in the solution state were administered to nude mice via urinary instillation, and the in vivo retention behavior of P407Gels was visualized by using an in vivo imaging system (IVIS). RESULTS: P407Gels showed a thermo-reversible phase transition at 4℃ (refrigerated; sol) and 37℃ (body temperature; gel). The G-Temp, G-Time, and G-Dur of FD-free P407Gels were approximately 10℃–20℃, 12–30 seconds, and 12–35 hours, respectively, and were not altered by the addition of FD. Fluorescence imaging showed that FD was spread homogenously in the gelled P407 solution. In a bladder simulation model, even after repeated periodic filling-emptying cycles, the hydrogel formulation displayed excellent retention with continuous release of the probe over 8 hours. The FD release from P407Gels and the erosion of the gel, both of which followed zero-order kinetics, had a linear relationship (r²=0.988). IVIS demonstrated that the intravesical retention time of P407Gels was over 4 hours, which was longer than that of the FD solution ( < 1 hour), even though periodic urination occurred in the mice. CONCLUSIONS: FD release from P407Gels was erosion-controlled. P407Gels represent a promising system to enhance intravesical retention with extended drug delivery.

Identification of Downstream Genes of the mTOR Pathway that Predict Recurrence and Progression in Non-Muscle Invasive High-Grade Urothelial Carcinoma of the Bladder

Microarray analysis was used to investigate the lack of identified mammalian target of rapamycin (mTOR) pathway downstream genes to overcome cross-talk at non-muscle invasive high-grade (HG)-urothelial carcinoma (UC) of the bladder, gene expression patterns, gene ontology, and gene clustering by triple (p70S6K, S6K, and eIF4E) small interfering RNAs (siRNAs) or rapamycin in 5637 and T24 cell lines. We selected mTOR pathway downstream genes that were suppressed by siRNAs more than 2-fold, or were up-regulated or down-regulated by rapamycin more than 2-fold. We validated mTOR downstream genes with immunohistochemistry using a tissue microarray (TMA) of 125 non-muscle invasive HG-UC patients and knockout study to evaluate the synergistic effect with rapamycin. The microarray analysis selected mTOR pathway downstream genes consisting of 4 rapamycin up-regulated genes (FABP4, H19, ANXA10, and UPK3A) and 4 rapamycin down-regulated genes (FOXD3, ATP7A, plexin D1, and ADAMTS5). In the TMA, FABP4, and ATP7A were more expressed at T1 and FOXD3 was at Ta. ANXA10 and ADAMTS5 were more expressed in tumors ≤ 3 cm in diameter. In a multivariate Cox regression model, ANXA10 was a significant predictor of recurrence and ATP7A was a significant predictor of progression in non-muscle invasive HG-UC of the bladder. In an ATP7A knock-out model, rapamycin treatment synergistically inhibited cell viability, wound healing, and invasion ability compared to rapamycin only. Activity of the ANXA10 and ATP7A mTOR pathway downstream genes might predict recurrence and progression in non-muscle invasive HG-UC of the bladder. ATP7A knockout overcomes rapamycin cross-talk.

Manipulating the Angiogenesis by Inflammation

There exists a need to develop strategies that promote neovascularization in virtually all tissue engineering and regenerative medicine efforts. While research typically focuses on understanding and exploiting the role of angiogenic factors and vascular cells on new blood vessel formation, the activity of the immune system is being recognized to impact vascular formation and adaptation. This review will provide both an overview of the relationship of angiogenesis and the immune system, and how biomaterials may be designed to promote favorable angiogenesis by interaction between these 2 systems to promote effective vascularization.

NBR1 and KIF14 Downstream of the Mammarian Target of Rapamycin Pathway Predict Recurrence in Nonmuscle Invasive Low Grade Urothelial Carcinoma of the Bladder

PURPOSE: The lack of identified mammalian target of rapamycin (mTOR) pathway downstream genes that overcome cross-talk in nonmuscle invasive low grade (LG)-urothelial carcinoma (UC) of the bladder is a clinical limitation in the use of mTOR inhibitor for the treatment of UC. MATERIALS AND METHODS: Presently, gene expression patterns, gene ontology, and gene clustering by dual (p70S6K and S6K) siRNAs or rapamycin in 253J and TR4 cell lines were investigated by microarray analysis. mTOR/S6K pathway downstream genes suppressed to siRNAs, and rapamycin up-regulated or rapamycin down-regulated genes were identified. The mTOR downstream genes examined using a tissue microarray of 90 nonmuscle invasive LG-UC patients to assess whether any of these genes predicted clinical outcomes. A knockout study evaluated the synergistic effect with rapamycin. RESULTS: In the microarray analysis, mTOR pathway downstream genes selected consisted of 4 rapamycin down-regulated (FOXM1, KIF14, MYBL2, and UHRF1), and 4 rapamycin up-regulated (GPR87, NBR1, VASH1, and PRIMA1). In the tissue microarray, FOXM1, KIF14, and NBR1 were more expressed at T1, and MYBL2, and PRIMA1 were more expressed in tumors exceeding 3 cm. In a multivariate Cox regression model, KIF14 and NBR1 were significant predictors of recurrence in nonmuscle invasive LG-UC of the bladder. In a NBR1 knock out model, rapamycin treatment synergistically inhibited cell viability and colony forming ability compared to rapamycin only. CONCLUSIONS: The results implicate KIF14 and NBR1 as mTOR/S6K pathway downstream genes that predict recurrence in nonmuscle invasive LG-UC of the bladder and demonstrate that NBR1 knockout overcomes rapamycin cross-talk.

Vascularization Methods for Tissue Engineers

Tissue engineering is limited by our inability to adequately vascularize tissues post implantation because all tissue-engineered substitutes (with the exception of cornea and cartilage) require a vascular network to provide the nutrient and oxygen supply needed for their survival. This review gives a brief overview of the processes and factors involved in the vascularization and angiogenesis and summarizes the different strategies to overcome the issue of slow vascularization and angiogenesis in a range of tissue-engineered substitutes. Moreover, we will announce some potential future plans.

Genetically Modified Bacteria as Targeted Agent for Cancer

With the emergence of microbiome as a major player in many human diseases, bacteria as therapeutics are gaining significant interest. Whole bacteria or cytotoxic or immunogenic peptides carried by them exert potent anti-tumor effects in the experimental models of cancer. The use of attenuated microorganism (s) e.g., BCG to treat human urinary bladder cancer was found to be superior compared to standard chemotherapy. While bacteria alone may not offer full therapeutic benefits, modifying them with anti-tumor agents, anti-oncogenes or immunogenic antigens, either alone or in combination, will prove to be beneficial. Vectors for delivering shRNAs that target oncogenic products, express tumor suppressor genes and immunogenic proteins have been developed. These approaches have showed promising anti-tumor activity in mouse models against various tumors. These can be potential therapeutics for humans in the future and such therapeutics may become a future alternative or adjunct regimen along with conventional chemotherapy and radiotherapy. In this review, some conceptual and practical issues on how to improve these agents for human applications are discussed.

Recombinant Bacille Calmette–Guérin for Immunotherapy in Nonmuscle Invasive Bladder Cancer

Intravesical instillation of Mycobacterium bovis bacille Calmette–Guérin (BCG) has been used for treating nonmuscle invasive bladder cancer as the forefront of immunotherapy, but BCG is ineffective in approximately 30–40% of cases and disease recurs in up to 50% of patients. Recently BCG is considered an effective vehicle for delivery of antigens due to its unique characteristics, and the genetic control of these mycobacteria is advanced in the search for less toxic and more potent therapeutic agents for bladder cancer immunotherapy. We will discuss current advances in recombinant BCG construction, research, and future directions.

RASSF1A Suppresses Cell Migration through Inactivation of HDAC6 and Increase of Acetylated alpha-Tubulin / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The RAS association domain family protein 1 (RASSF1) has been implicated in a tumor-suppressive function through the induction of acetylated alpha-tubulin and modulation of cell migration. However, the mechanisms of how RASSF1A is associated with acetylation of alpha-tubulin for controlling cell migration have not yet been elucidated. In this study, we found that RASSF1A regulated cell migration through the regulation of histon deacetylase 6 (HDAC6), which functions as a tubulin deacetylase. MATERIALS AND METHODS: The cell migration was assessed using wound-healing and transwell assays. The role of RASSF1A on cell migration was examined by immunofluorescence staining, HDAC activity assay and western blot analysis. RESULTS: Cell migration was inhibited and cell morphology was changed in RASSF1A-transfected H1299 cells, compared with controls, whereas HDAC6 protein expression was not changed by RASSF1A transfection in these cells. However, RASSF1A inhibited deacetylating activity of HDAC6 protein and induced acetylated alpha-tubulin expression. Furthermore, acetylated alpha-tubulin and HDAC6 protein were co-localized in the cytoplasm in RASSF1A-transfected H1299 cells. Conversely, when the endogenous RASSF1A expression in HeLa cells was blocked with RASSF1A siRNA treatment, acetylated alpha-tubulin was co-localized with HDAC6 protein throughout the whole cells, including the nucleus, compared with scramble siRNA-treated HeLa cells. The restoration of RASSF1A by 5-Aza-dC treatment also induced acetylated alpha-tubulin through inhibition of HDAC6 activity that finally resulted in suppressing cell migration in H1299 cells. To further confirm the role of HDAC6 in RASSF1A-mediated cell migration, the HDAC6 expression in H1299 cells was suppressed by using HDAC6 siRNA, and cell motility was found to be decreased through enhanced acetylated alpha-tubulin. CONCLUSION: The results of this study suggest that the inactivation of HDAC6 by RASSF1A regulates cell migration through increased acetylated alpha-tubulin protein.

No Association between Promoter Polymorphism of STK11 Gene and Lung Cancer Risk in the Korean Population / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Serine-threonine kinase11 (STK11) was originally identified in 1997 as the causative mutation that's responsible for Peutz-Jeghers Syndrome (PJS). Several recent studies have reported that the STK11 gene is an important human tumor suppressor gene in lung cancer. We evaluated the associations between the polymorphisms of the STK11 promoter region and the risk of lung cancer in 901 Koreans. MATERIALS AND METHODS: By direct sequencing, we first discovered three novel polymorphisms (-1,795 T>C, -981 C>T and -160 G>T) and four known polymorphisms (-1,580 C>T, -1,494 A>C, -881 A>G and -458 G>C) of the STK11 promoter region in 24 blood samples of 24 Korean lung cancer patients. Further genotype analyses were then performed on 443 lung cancer patients and 458 controls. RESULTS: We discovered three novel polymorphisms and we identified four known polymorphisms of the STK11 promoter region in a Korean population. Statistical analyses revealed that the genotypes and haplotypes in the STK11 gene were not significantly associated with the risk of lung cancer in a Korean population. CONCLUSION: This is the first study that's focused on the association of STK11 promoter polymorphisms and the risk of lung cancer in a Korean population. To evaluate the role of the STK11 gene for the risk of lung cancer, the genotypes of the STK11 promoter region (-1,795 T>C, -1,494 A>C and -160 G>T) were determined in 901 Koreans, yet the result revealed no significant difference between the lung cancer patients and the controls. These results suggest that the three promoter polymorphisms we studied are not important risk factors for the susceptibility to lung cancer in Koreans.

Combinational Treatment with Retinoic Acid Derivatives in Non-small Cell Lung Carcinoma In Vitro

The growth inhibitory effects of four retinoic acid (RA) derivatives, 9-cis RA, 13-cis RA, N-(4-hydroxyphenyl) retinamide (4-HPR), and all-trans retinoic acid (ATRA) were compared. In addition, the effects of various combinations of these four agents were examined on non-small cell lung carcinoma (NSCLC) cell-lines, and on the expressions of retinoic acid receptors (RARs) and retinoid X receptors (RXRs) on these cells. At the clinically achievable concentration of 1 micrometer, only 4-HPR inhibited the growths of H1299 and H460 cells-lines. However, retinoic acid receptor beta(RAR beta) expression was up-regulated on H460 and H1299 cells treated with 1 micrometer of ATRA, 13-cis RA, or 9-cis RA. All NSCLC cell lines showed growth inhibition when exposed sequentially to 1 micrometer ATRA and 0.1 micrometer 4-HPR. In particular, sequential treatment with 1 micrometer ATRA or 13-cis RA and 4-HPR markedly inhibited H1703 cell growth; these cells exhibited no basal RAR beta expression and were refractory to 4-HPR. However, in NSCLC cell lines that expressed RAR beta, the expressional levels of RAR beta were up-regulated by ATRA alone and by sequential treatment with ATRA and 4-HPR. 4-HPR was found to be the most active of the four agents in terms of NSCLC growth-inhibition. Moreover, sequential treatments with ATRA or 13-cis RA followed by 4-HPR were found to have synergistic growth-inhibitory effects and to regulate RAR expression.

AKAP12alpha is Associated with Promoter Methylation in Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Promoter methylation is an important mechanism for silencing tumor-suppressor genes in cancer and it is a promising tool for the development of molecular biomarkers. The purpose of the present study was to investigate whether inactivation of the A Kinase Anchoring Protein 12 (AKAP12) gene is associated with promoter methylation in lung cancer. MATERIALS AND METHODS: The AKAP12 expression was examined by reverse transcription-polymerase chain reaction (RT-PCR) in ten lung cancer cell lines. The methylation status of the AKAP12alpha promoter was analyzed by performing bisulfite sequencing analysis in ten lung cancer cell lines, twenty four lung tissues and matched normal tissues. RESULTS: The AKAP12alpha expression was reduced in 6 of 10 (60%) lung cancer cell lines, whereas the AKAP12beta expression was absent in 1 of 10 (10%) lung cancer cell lines. The AKAP12alpha expression was restored after treatment with the demethylating agent 5-aza-2'-deoxycytidine in three lung cancer cell lines. Methylation of CpG island 1 in the AKAP12alpha promoter was detected in 30% of the lung cancer cell lines, whereas methylation of CpG island 2 in the AKAP12alpha promoter was observed in the immortalized bronchial cell line and in all the lung cancer cell lines. In lung tumors, the CpG island 1 in the AKAP12alpha promoter was infrequently methylated. However, CpG island 2 in the AKAP12alpha promoter was highly methylated in lung tumors compared with the surrounding normal tissues, and this was statistically significant (p=0.0001). CONCLUSION: Our results suggest that inactivation of the AKAP12alpha expression is associated with DNA methylation of the promoter region in lung cancer, and that AKAP12alpha may play an important role in lung cancer carcinogenesis.

Retinoic Acid Enhances Drug-Induced Cell Death in Anticancer Drug-Resistant Cell Lines / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Retinoids (RA), a group of vitamin A derivatives, is known to be important for regulation of normal cellular growth and differentiation. RA treatment of various cancers resulted in cell growth inhibition and apoptosis. Therefore, the chemotherapeutic and chemopreventative activities of various types of tumor have been examined. Biological actions of RA are mediated through nuclear receptors, including the retinoic acid receptors (RARs) and retinoid X receptors (RXRs). In this study, we examined the effect of all-trans-retinoic acid (atRA) as an anticancer drug-sensitiser in cancer cell lines and in its drug- resistant cancer cell lines MATERIALS AND METGODS: Cells were maintained by RPMI 1640 medium containing 10% fetal bovine serum. Cells were treated with 1 micro M atRA for 48 h, then with the desired concentration of anticancer drug for 24 h. Cell viability was measured spectrophotometrically at 540 nm using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. Western blot analyses were performed with the desired antibodies. RESULTS: We investigated if pre-treatment with atRA enhanced the drug-sensitivity of various cancer cell lines to either 5-fluorouracil, adriamycin, or cisplatin. 5-FU (SNU638-F2) and CDDP-resistant cell (SNU638-Cis) lines, from a Korean gastric cancer cell line (SNU638) and the ADR-resistant cells (AD600) was established from a colon cancer cell line (SW620). Treatment of each cell line, with 1 micro M atRA, prior to drug exposure resulted in enhanced cell death in these cell lines. Furthermore, the effect of atRA on growth inhibition, in each drug-resistant cell line, was more obvious than in their parent cell lines. Increased activity of Transglutaminase II (TgaseII) and cleavage of Poly (ADP-ribose) polymerase (PARP) were also observed (western blot analysis CONCLUSION: Based on our data, we suggest that atRA enhances anticancer drug-induced cell death and reverses the drug-sensitivity of the drug-resistant cancer cell lines.